The invention relates to an apparatus for indicating the level in metallurgical vessels, more particularly tundishes for the casting of molten steel into ingot molds, comprising electromagnetic coils that are arranged in the wall of the vessel with axes directed to the bath and are developed as primary or transmitting coils connected to alternating current and as secondary or receiving coils, and whose alternating voltages induced in direct relation to the bath level serve as input signals for a data processing unit.
In this type of device, such as, for example the device disclosed in Printed West German Unexamined Patent Application No. OS 27 22 214 and U.S. Pat. No. 4,144,576, the transmitting coil and the receiving coil are provided separately in the refractory lining at various points of the vessel, e.g. in the area of the corner of a melting furnace on two adjoining or two opposing walls of a vessel. With this design, a special cable consisting of an inner wire, a heat-resistant ceramic insulation and an outer steel pipe are used to form the coils. In principle, separate coil arrangements are relatively expensive and cumbersome during assembly, because each coil must be mounted separately at the assigned point of the vessel lining, whereby the cooperating coils must be aligned accurately to each other so as to obtain usable output signals.